SAN JOSE, Calif. -- San Jose State University has expelled three students accused of bullying and tormenting their black roommate by putting a bike lock around his neck and calling him derogatory names.

A fourth student has been put on probation for the rest of his college career if he returns, the San Jose Mercury News reported.

The four students, who are white, have pleaded not guilty to misdemeanor battery and hate crime charges. They are accused of putting the bike lock on then-freshman Donald Williams and taunting him with racial slurs, locking him in his room and waving a Confederate flag.

Earlier this year, Williams filed a $5 million claim against the university.

The expelled students are banned from enrolling in any California State University college, according to university documents obtained by the newspaper.

"It's a no-brainer," said LaDoris Cordell, a retired judge and city police watchdog. "They have no business being enrolled at SJSU."

A lawyer for one of the expelled students said the school didn't conduct a thorough review.

"We were very disappointed with the school's process," attorney Eric Geffon said. "It was clear early on they had already made up their mind."

Joseph Bomgardner, 19, was the only student who was not expelled. He agreed to the suspension and other sanctions without admitting his participation. He has to complete counseling and attend a follow-up meeting with school officials. If he decides to return to school, he will be placed on permanent probation.

The lighter punishment "may give an inkling of the participation or lack of it of my client," Bomgardner's lawyer Sam Polverino said.

A university spokeswoman said the school can't comment on disciplinary matters.

In the wake of the incident, San Jose State set up a task force to review Williams' case. The task force determined the school waited too long to discipline the students accused of bullying Williams. It made several recommendations, including more diversity training for employees and students and a mobile app for reporting hate crimes.